Various structural components are used to form a typical aircraft. For example, wing and empennage surfaces of an aircraft typically include stringers that are coupled to skin members on the wing and empennage surfaces that cooperatively provide a desired flexural and torsional stiffness to the wing and empennage surfaces.
Aircraft structures may be formed from composite materials, which are generally reinforced polymer-based materials used in place of metals, particularly in applications in which relatively low weight and high mechanical strength is desired. Composite materials are widely used in a variety of commercial and military aircraft, terrestrial vehicles and consumer products. A composite material may include a network of reinforcing fibers that are generally applied in layers, and a polymeric resin that substantially wets the reinforcing fibers to form a binding contact between the resin and the reinforcing fibers. The composite material may then be formed into a structural component by a variety of known forming methods, such as an extrusion process or other forming processes.
Certain aircraft include winglets extending from distal ends of main wing structures. Winglets are configured to reduce drag, such as by partially recovering tip vortex energy. Various winglets are configured to increase lift generated at the wingtip (by smoothing airflow across the upper wing near the tip) and reduce lift-induced drag caused by wingtip vortices, thereby improving lift-to-drag ratio.
Ultrasound probes may be used to scan structures (such as composite or metal wings, fuselage, and the like of an aircraft) to assess a condition of the structure. Nondestructive inspection (NDI) techniques are used to inspect leading edges of winglets. For example, NDI techniques are used to detect imperfections, such as delaminations, in composite winglets. The leading edge of a winglet generally includes an asymmetrically shaped parabolic cross section that varies in size and shape between inboard and outboard areas.
Ultrasonic inspection of composite structures generally includes pulsing and receiving elements that are disposed normal to a surface of the part being inspected. Due to the asymmetric size and shape of winglets, however, such normal orientation may be difficult or impossible to achieve.
Accordingly, a need exists for a system and method for efficiently inspecting an irregularly-shaped composite structure, such as a winglet of an aircraft.